1. Field of the Invention
The present invention relates to a system operable to fabricate an electric circuit by performing predetermined working operations on a circuit substrate, such as an operation to mount electric components (including electronic components) on the circuit substrate, a method of performing such working operations to fabricate the electric circuit, and a control program executed by a computer to perform the working operations for fabricating the circuit substrate.
2. Discussion of Related Art
In some working devices arranged to perform working operations on circuit substrates, such as an electric-component mounting device, a solder-paste applying device, and an adhesive applying device, the circuit substrates are identified when the working operations are performed on the circuit substrates. In an electric-circuit fabricating or manufacturing system including such working devices arranged in a line, for example, the recognition or identification of the circuit substrates is particularly important, in view of different kinds or configurations of the circuit substrates to be handled.
Conventionally, the circuit substrates are identified by recognizing substrate identifiers in the form of substrate-identification marks such as bar codes. For instance, this identification is effected on the working device disposed upstream of the working device in question on which a working operation is performed on the circuit substrate, or on a substrate loading device provided to load the circuit substrate onto the working device in question. In other words, the identification of the circuit substrate on which the working operation is performed is effected at a position or location which is distant from or outside the working device which performs the working operation on the circuit substrate.
Where the identification of the circuit substrates by recognizing the substrate identifiers is effected at a location outside the working device on which the working operation is performed on the circuit substrate, as described above, the location of identification is distant from the location of the working operation to be performed, so that there may arise a failure of the circuit substrate to reach the working device in question, or a change in the order of arrangement of the two or more substrates existing between the location of identification and the location of the working operation. In this respect, the conventional manner of effecting the identification of the circuit substrates does not assure a high degree of stability in the consistency between the kind of the circuit substrate and the contents of the working operation to be performed on that circuit substrate. Further, the substrate identifiers are recognized by an exclusive identifier-recognition device disposed at the location of identification of the circuit substrates. In this respect, it is noted that the substrate identifiers are not located at the same positions on all of the circuit substrates to be handled, so that a change in the kind of the circuit substrate on which the working operation is performed may require a change in the location of the identifier-recognition device, which results in an increase in the required time for a setup changeover of the electric-circuit fabricating system.